Eastlake-SY131016 ••• HALFF
October 16, 2013
AVO 28875 W002
Mr. Michael Garza,P.E.
Civil Engineer 1L,r11�
City of Coppell
PO Box 9478
Coppell, Texas 75019
Re: Review of Floodplain Study Submittal by Kimley-Horn and Associates, Inc. —
Conditional Letter of Map Revision (CLOMR) for Easthaven Residential
Development—Denton Creek
Dear Mr. Garza,
We have completed the technical review of the Conditional Letter of Map Revision (CLOMR)for
Easthaven Residential Development — Denton Creek prepared by Kimley-Horn and Associates,
Inc., dated May 3, 2013, revised July 8, 2013, revised on October 9, 2013, and received on
October 10, 2013. As of result of this review, we believe that the stream hydraulics and
floodplain mapping on Denton Creek for the Easthaven Residential Development along Denton
Creek generally conforms to City of Coppell floodplain ordinance, regulations and policies.
The following comments are a result of this review:
1. The proposed project seems to have no significant impact on water surface elevations on
Denton Creek.
2. The proposed project seems to have no significant impact on velocities on Denton Creek.
3. Valley storage loss on Denton Creek due to the project does not exceed the maximum
allowable of 15%. Valley storage reductions for the standard project flood event was not
determined since the proposed project modifications have no significant impact on the
standard project flood backwater elevation from the Elm Fork of the Trinity River.
4. A final report that has been signed and sealed by a Professional Engineer in the State of
Texas will need to be submitted before final approval is granted.
Based on this information, Halff Associates recommends conditional approval. Full approval
can be granted once Item 4 above has been addressed.
HALFF ASSOCIATES,INC.
1201 NORTH BOWSER ROAD TEL (214)346-6200 WWW.HALFF.COM
RICHARDSON,TX 75081-2275 FAX (214)739-0095
NNE HALFF
This review was performed for the benefit of the City of Coppell. This is not a detailed
engineering review of any construction plans, and Halff Associates, Inc. assumes no liability for
the adequacy of the planning, design or construction of the project.
Do not hesitate to call me at 214-346-6245 if you have further questions or comments
concerning this review. Please include the reference "AVO 28875 W002" on all
correspondence.
Sincerely,
HALFF ASSOCIATES,INC.
liA"Neuee,
Russell P. Erskine, P.E., CFM
Project Manager
cc: Kate E. Hagan, P.E.
Kimley-Horn and Associates, Inc.